Posted
by
Soulskillon Saturday March 01, 2014 @02:52PM
from the how-talking-with-your-hands-becomes-untenable dept.

An anonymous reader sends this news from the University of Washington:
"[C]omputer scientists have built a low-cost gesture recognition system that runs without batteries and lets users control their electronic devices hidden from sight with simple hand movements. The prototype, called 'AllSee,' uses existing TV signals as both a power source and the means for detecting a user's gesture command (PDF). 'This is the first gesture recognition system that can be implemented for less than a dollar and doesn't require a battery,' said Shyam Gollakota, a UW assistant professor of computer science and engineering. 'You can leverage TV signals both as a source of power and as a source of gesture recognition.' The researchers built a small sensor that can be placed on an electronic device such as a smartphone. The sensor uses an ultra-low-power receiver to extract and classify gesture information from wireless transmissions around us. When a person gestures with the hand, it changes the amplitude of the wireless signals in the air. The AllSee sensors then recognize unique amplitude changes created by specific gestures."

In the ancient days of my youth I connected a short wire to the grid of of a simple vacuum tube and monitored the plate current on a meter. As I moved around the room the meter current fluctuated. This illustrates just how sensitive electronics are.

OK, so the effect of body position and proximity on a received signal has been known for a long time. Interpreting it and assigning meaning isn't that big a stretch, I guess. But to combine that with this kind of low (no?) power implementation is brilliant!

I suppose some killjoys will complain that the parts of the world most in need of low power tech are also those most lacking in the ambient signals needed to make this work. Pffft! This is simply brilliant.

so it works in a big open park in the middle of a city. it doesn't work at all in the middle of a farm, or between cities. It's sketchy on the street between two buildings. And it's intermittant in the underground parking garage.

Think about it this way, Radio waves are just electromagnetic waves like light. It's all around us. Our eyes can detect it bouncing off other things. This is just a eye that can detect the radio waves reflecting off of things. Astronomers do this all the time with radio telescopes, which I would figure these guys used a bunch of their concepts for this.The really major part of doing this is knocking out the noise to be able to discern the motion. That, I

You still need power to act on the recognized gestures. But to output a small set of states it does not consume power and uses ambient energy. Looks like they recognize some four or five gestures. Hand coming in, hand going out, fist. Mixing them temporally, they may be able to get some 8 different states. It can lead to always on sensors, but even to act on the recognized sensors you need an always on actively powered (not ambiently powered) system.